In dental implantology as currently being practiced it is common to use rotation-limiting connecting mechanisms consisting, for example, of a hexagonal post or socket on an implant and a mating socket or post on an article intended to be attached to the implant. There being a wide variety of such articles (posts, copings, artificial teeth, etc.), it is the prevailing manufacturing practice to employ standard sizes of such posts and sockets so that all such articles will fit interchangeably on all available implants of a given manufacturer. The dimensions being used are small. Owing in part to the limitations of manufacturing tolerances, the sockets are a little larger across than the posts in order to assure that in every case the dentist will be able to put two parts together at chairside, and when necessary to take them apart without difficulty. Typically, the distance between opposing flat surfaces of a hexagonal post may be about 0.0005 inch smaller than the distance between opposing flat surfaces of a mating hexagonal socket. While this arrangement provides an essential rotation-limiting connection, it leaves a small amount of rotational looseness which is undesirable in that it does not provide the stability of a natural tooth. More importantly, the rotational wiggling between parts creates an environment in which the screw that holds an article fixed to an implant can work itself loose. It is critically important to a successful dental restoration on an implant that the restoration not come loose on the implant.